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Uncertainty in Global Warming Science

Posted on 26 June 2011 by hfranzen

Since the time of Kepler and Galileo there Galileohas been steady progress in the precision with which humans can predict the outcome of kinematic events.  As is well known, major advances were made by Newton and Einstein and today we can predict with extraordinary accuracy the trajectory of an object traveling with a known velocity under the influence of gravitational forces. 

This does not mean that the trajectory of a rocket traveling to Mars, for example, is known with absolute precision but is to some extent uncertain.  In part this uncertainty is introduced both by our inability to determine the velocity with perfect precision and by the perturbations of gravitational effects arising from  more distant objects.  

KeplerTherefore it is correct to say,  even in this very well understood case, that the results of the scientific calculation are “uncertain”.  Such uncertainty is a reality in all scientific calculations and those who depend upon the results of such calculations must be aware of this fact.  However in cases of the character of rocket trajectory calculations the uncertainties themselves are understood such that we can be very certain that a rocket meant to go to Mars will arrive there barring some unforeseen catastrophe such as an engine failure or a giant solar flare.

In the same fashion there are many areas in our lives (communication, GPS, air traffic control, cat scans, MRI, internal combustion, electric generation and transmission, radar, computer automation, etc.)  that depend upon the results of science and have associated with them uncertainties  that are both known and known to be negligible in terms of  the particular application to which the relevant science (electromagnetism, quantum mechanics, classical mechanics , etc.) is applied.  This is simply to state an obvious fact of our lives in the 21st century. In this essay I will distinguish between three types of science,

  • What I have briefly described above is a type of science that I will, for convenience, call Type A. I will take science to be of Type A if, in principal, the uncertainty in the result and the uncertainty in that uncertainty can be numerically calculated and the relative uncertainties in each can be determined to be less than some set percentage.
  • For me, then, Type B science depends on equations that are less precisely constrained than in Type A science.  In the case of Type B science there is difficulty in defining quantities and boundary conditions.  The equations in Type B science  cannot be solved with the same precision as for Type A and, equally important, the uncertainty in the uncertainty is frequently unknown.  An example of a result of Type B science is the prediction of weather.  We may be told, for example, that  there is a 75% chance of rain in our area. This “prediction” is based upon the understanding that meteorologists have of the basic equations governing the movement of air masses , the changes of temperature and pressure with such movement and the condensation of water  vapor, however the conditions limiting the equations in this case, the boundary conditions, are not so precisely defined and  the objects to which the equations apply not so well defined as in the previous cases.

    The conclusions of Type B science have a much greater range of relative uncertainty than for Type A. The 25% uncertainty suggested by the 75% probability would of course be totally unacceptable in a Type A calculation of, say, the osmotic pressure of an injected serum or the probability of a mid-air collision. Furthermore, the uncertainty in that 25% uncertainty in the weather itself is, from everyday experience, quite a bit larger than would be acceptable for placing a lander on Mars or determining the locations of neighboring planes in the vicinity of an airport.  This, by the way, is not to demean meteorology – given the complexity of the problem the meteorologists do a marvelous job!
  • Then there is Type C science.    A major tool of what I call Type C science is curve fitting.  One seeks to fit a curve  to data using parameters with no apriori physical meaning,  but that provide the smallest residual “error” .  In many cases it is the best that can be done, but the results are inevitably open to doubt.  An example is the growth of a population with time where an observer fits the data to a population vs. time curve and uses this to interpolate or extrapolate populations to times for which measurements are not available.  Such curves are always open to question even though in the hands of  skilled observers they may be used to reach significant conclusions (examples of Type C science are Malthus' population prediction and the Keeling Curve).

Now, finally, I will turn my attention to global warming.  My concern in this essay is that science of all three types is applied to global warming and frequently, when the validity of conclusions is under discussion, no distinction is made between the three types of science.  Taking the earth’s temperature as a function of time as an example, many deniers have focused on the uncertainties associated with the interpretation of tree ring or ice core data.  In my view this is acceptable to a certain extent.  Skepticism is a healthy component of scientific analysis and I believe that those who have made the measurements and compiled the data can and do adequately defend their conclusions.  But it is my personal view that global warming is based first and foremost upon the conclusion of Type A science (the interaction of the earth’s  Planck radiation with the rot-vib modes of atmospheric carbon dioxide and the experimental and theoretical determination of the extent of this interaction ). It is also my view that only upon the basis of Type A science is one able evaluate the Type C science inherent in fitting the earth’s temperature to time. 

A major problem, as I see it, is that when deniers question the Type C science without coming to grips with the underlying Type A science they can deceive themselves and others into believing that they are attacking the basic structure of global warming science whereas in reality they are just dealing with a detail in the superstructure. They may in fact be dealing with a detail within a detail, e.g. selecting for discussion a particular subset of data (“cherry picking”). On the other hand to deny the Type A science showing global warming without finding a flaw in the argument (see hfranzen.org for a basic discussion of the effect without feedbacks or interferences) is like saying , ”I accept almost all of mathematics but deny the validity of Euler’s Theorem”. Just as it would make sense to deny Euler’s Theorem only if one could disprove it, it makes no sense to deny global warming science without finding a logical flaw in the Type A science demonstrating GW while, as I claim almost everyone does, accepting the myriad results of Type A science that come into play in our daily lives. And further it makes no sense to attack the average earth temperature vs. time (hockey-stick) curve without first coming to grips with the Type A science of GW.  To my way of thinking the hockey stick is not the basis of GW science, it is derivative and confirmatory, and its basic correctness depends upon the fundamental Type A science underlying the temperature changes.

The gist of what I am saying is this – when deniers confront an issue dealing with Type C science they should be asked to first consider the question, “Do you accept the basic  conclusion of quantum mechanics and spectroscopy that global warming is occurring  right now?” If their answer is “no” than it seems to me that  it is Type A science that should be debated before tackling the Type C science.  If their answer is yes, then, importantly, it is not possible for them to take the fact of the debate as a demonstration that the major thrust of the science of global warming is basically flawed. Furthermore any discussion of some aspect of the Type C science can be meaningfully limited to the relevant issue without  trying to discuss the larger question of the validity of the underlying GW proposition.

In short, if a denier disputes the claims of the hockey stick and is unwilling to accept the basic science of absorption of infra-red radiation by carbon dioxide then it is fruitless to discuss the hockey stick with that denier.  On the other hand if they accept the basic science but deny the hockey stick then it can be worthwhile exploring  their concerns  and pointing out that the hockey stick result follows straightforwardly, if not rigorously, from the known increasing energy input into the earth.  In the discussion that follows they might  be able to present some basis for criticism of the hockey stick curve beyond the fact that they simply don’t want to believe in global warming, and if the criticism is valid this would be a win-win situation.

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Comments 1 to 50 out of 75:

  1. "On the other hand if they accept the basic science but deny the hockey stick then it can be worthwhile exploring their concerns and pointing out that the hockey stick result follows straightforwardly, if not rigorously, from the known increasing energy input into the earth." Quite right. So what is the value of the "known increasing energy input into the Earth".? It it 0.9W/sq.m from Hansen 2005 or 0.59W/sq.m from Hansen 2011?
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  2. 1, Ken, If you have a point, make it. Posting nothing but questions just demonstrates a continued need to sew doubt without even attempting to look for or wanting to find the answers.
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  3. Type A = AGW. Type C = CAGW.
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  4. 1, Ken, My apologies. In re-reading things, you were obviously trying to (humorously) emphasize exactly the point that Dr. Franzen was trying to make with a rather subtle Poe (so subtle, that I missed it). Well done. Thank you. Just to answer your question, however, the 0.85 W/m2 figure from Hansen 2005 was derived from GISS climate model runs from 1880 to 2003, while the 0.59 W/m2 figure from Hansen et al 2011 was for the period from 2005 to 2011. Hansen et al 2011 also contains an estimate of 0.80 W/m2 for the period from 1993-2008, and 0.70 W/m2 for 2003-2008. Error bars are included with all estimates, and all use a variety of papers and techniques as sources for the computations. Different techniques, over different time periods, would of course yield different results. Everyone knows the system is chaotic, and includes substantial noise as well as impediments to direct measurement. As I've already said, this is in fact a main point of Dr. Franzen's post, and that you have highlighted this with your question (one a little more nuanced than a simple "hockey-stick" reference) does in fact help to clarify his main point, which is that once one accepts the science, then arguing about the measured details is worthwhile and necessary. But the answer to your question is easily determined simply by looking at the actual content of the two papers you sited. From Hansen 2005, Table 1:
    Effective climate forcings (W/m2) used to drive the 1880 to 2003 simulated climate change in the GISS climate model
    From Hansen et al 2011:
    Our estimated planetary energy imbalance is 0.80 ± 0.20 W/m2 for 1993-2008 and 0.59 ± 0.15 W/m2 for 2005-2010, with estimated 1-σ standard error. Our estimate for 1993-2008 uses the Lyman et al. (2010) ocean heat gain rather than Levitus et al. (2009) for the reason discussed in section 10. The estimated error in 2005-2010 is almost as large as that in 1993-2008 because of the brevity of the period. Sampling error in the Argo era will decline as the Argo record lengthens (von Schuckmann and Le Traon, 2011), but systematic biases may remain.
    There is much more in both papers. I'm sure that if you read them in their entirety, you'll find the answers to any questions you may have.
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  5. @Sphaerica#4: Your statement, "Everyone knows the system is chaotic, and includes substantial noise as well as impediments to direct measurement." may not be understandable to the average person reading this comment thread. Please elaborate.
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  6. 5, Badgersouth, Very simply, in reference to Ken's specific area of interest (system imbalance in W/m2), this is going to depend on a lot of factors, including the functioning of every mechanism involved in energy transfer (radiation, GHGs, latent heat, evaporation, albedo, clouds, insolation, etc.). It is going to be impacted by all sorts of periodic but variable and unpredictable events (ENSO, PDO, etc.). Basically, everything that makes global temperatures vary from day to day, week to week, and year to year is also going to make the energy imbalance vary. For example, my guess would be that in a year when the global mean temperature appears to be lower, the energy imbalance is liable to be greater (since a cooler body will radiate less). At the same time, measuring the imbalance is difficult, and so a variety of different methods and efforts are needed to do so. Actually, a fleet of satellites, had they been launched when needed a decade ago, might have helped to close that loop and accurately measure what we need to know, but that never happened. Not nearly enough was put into new satellites, many were lost at launch, and one (the Deep Space Climate Observatory) was in fact the only satellite in history ever to be built by NASA (at a cost of $100 million) and never launched. To this day it sits in a warehouse, even though arrangements were made to launch it for free (it's built, the launch would be free, but NASA said that it was too much of a danger to the satellite, so instead it sits uselessly in a warehouse). There are so many factors and variables, and it is so difficult to measure everything involved accurately, that to expect to balance the ledger and to so accurately measure the "known increasing energy input" is unrealistic. All we can say for certain is that it is unquestionably increasing, we can bound that increase, and we know that if it is increasing, as is expected by our understanding of the physics, then the planet must be warming. This is what I mean when I say that the system is too chaotic, and there is too much noise, to expect to arrive at a single, unchanging value for the energy imbalance in the system, or to measure even a changing value given the tools that we have deployed today.
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  7. Sphaerica: You are finally talking logically. Thank you. It is not all clear, cut and dried.
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  8. 7, Camburn, Please read Dr. Franzen's post. It would do you good. Also, when you say "it is not all," this implies that you yourself do recognize that there are things that are clear, cut and dried (and in fact there are many). Would you care to itemize the aspects of climate science that you do not dispute? Could you list the elements of climate science that are beyond debate and point to a serious issue that cannot be ignored simply because some people like to find and harp on the rather meager areas of doubt and quantification that, in the larger scheme of things, do not really greatly affect our need to very soon take moderate but effective action, but which can unfortunately be exaggerated to give that appearance?
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  9. Camburn Just keep in mind - not being able to ascertain exact numbers for increasing energy in the climate system does not mean you can assert that we don't have increasing energy in the climate system. We have far, far too much evidence pointing to warming to conclude that. It (global warming) is happening, identifying tight bounds on the trends and rates takes 20-30 years of data to extract from the noise, internal variability, and measurement error - and likewise, 20-30 years of data would be required to establish that things had changed and that we were cooling. But given the physics (type A science, as discussed above), that's just not going to happen unless we decrease the levels of CO2 in the air.
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  10. 7, Camburn, FYI, the insulting implication that I was not talking logically prior to this was duly noted, not appreciated, and unnecessary.
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  11. Sphaerica: My comment is an observation, not meant in an insulting way. 1. I agree 100%. Global warming is happening. The rate that it happening on a climatic scale is not actually alarming. When one looks at the long term mean, century scale means, one understands that the current temperature is not a dramatic one. 2. We all know that co2 is rising. 3. Where I will disagree is that from paleo studies, co2 is not what one would consider to be a prime driver of climate. 4. I am all for slowing the use of fossil fuels. They are a finite resource. The easy mining/drilling etc spots are becoming less and less. The economic shock of when, which in my opinion is happening now, of the increased costs of fossil fuels will continue the trend of economic uncertainty which is not good for mankind as a whole. 5. From a purely economic understanding, it is very easy to show that the cost of renewables, hydro, nuclear, geo thermal are practical and necessary in the long run. These are certainties. In my humble opinion, the use of AGW to try and incorporate change is a poor choice. The uncertainties of AGW allow and encourage resistance to change. A by product of the economic certainties in relation to the diminishing fossil fuel availability will drive emission of co2 down. That is a good thing, and an easy sell isn't it? Everyone is familiar with economic activity. Not everyone is familiar with climate. Go where the stregth of the data is, use that stregth.
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  12. KR: Using a short term anomoly of only 20 or 30 years does not prove anything is happening climatically. 20 or 30 years can easily be a cycle, rather than a change. The long term mean, century mean, is a valuable tool to detect discernable change.
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  13. One thing that is important to understand is what we do not know, and what is changing. Our understanding of the effects of solar on climate is only beginning to be understood. An example of recent changes is in this paper. A measurement that has been used has been found not to apply to the current state of the sun. Important reserach, the L&P effect, etc. magnetic effects, just a few items. F10 Flux
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  14. Hfranzen: I am very interested in your categorization of types of science. It seems to me that there is something important here which we should communicate better. In particular, there are theories which are proven through many different experiments and many other testable theories build on them. Some are the basis for everyday technology. Other theories are so specific as to have been untested beyond a single experiment. This must be useful in determining confidence in a particular result. (This of course relates to Popper's idea of a severe test, although quantifying confidence in a theory remains almost impossible owing to the challenge of identifying whether a test is severe and independent of other tests. Even in Bayesian hypothesis testing you are limited by the coverage of your alternate hypotheses.) Having sparked with your article my interest in this area, I want to look into it further. My questions are as follows: Is your classification rooted in any standard work in history or philosophy of science? Do you know of any previous efforts to classify types of science like this?
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  15. 11, Camburn,
    When one looks at the long term mean, century scale means, one understands that the current temperature is not a dramatic one.
    This statement is false and unsupportable in any objective frame of reference.
    Where I will disagree is that from paleo studies, co2 is not what one would consider to be a prime driver of climate.
    This statement is at best misleading. First, if you understand the physics, then you know that very few mechanisms are pure "drivers" of climate, so the whole phrasing of the statement is inaccurate. Almost everything that affects climate is both a driver and a feedback. Separating the two can be difficult, but is not always that relevant (in that the trigger for climate change is important for one reason, but the major feedbacks that exacerbate that change are every bit as important, if not more so). If your definition of a driver is "something that initiated" a change in climate, then you are partially right (the jury is out in those instances, such as the PETM, where CO2 may or may not have initiated climate change), but then this statement bears no relevance to our current dilemma. The fact that an intelligent race of beings has never before existed on the planet to burn the carbon that took millions of years to sequester is in no way an argument that it cannot be of consequence today. If your definition of a driver is "something that is a major and critical factor in climate change, regardless of the initial forcing" then you are dead wrong. CO2 concentrations are very definitively and demonstrably related to climate change throughout the past, I believe completely without exception, and to claim otherwise is to live in convenient denial with a very poor understanding of past climate change on earth.
    ...the use of AGW to try and incorporate change is a poor choice.
    This is where you run completely off the rails. No one is "choosing" to "use" AGW to try to and incorporate change. This particular conspiracy fantasy is both ridiculous and unsupportable. At what point did some group of people get together and decide to do this? Have you been at any of our monthly meetings where we discuss our strategies for how to trick the world into changing their energy infrastructure, for some other twisted and nefarious reason that has nothing whatsoever to do with climate change itself? Have you heard anyone say that they don't actually believe in climate change, but it's a convenient excuse to put the oil companies out of business a little early? Do you see how absurd that position is? Based on your responses, you do not understand or accept Dr. Franzen's Type A science... the simple prospect that climate change can and is happening, based on an indisputable understanding of the physics involved. Your denial is not in the degree of warming, but in the actual foundations of the proposition of climate change. Given this, as Dr. Franzen stated (somewhat differently) in his closing paragraph, discussion of any aspect beyond the basics of the science is fruitless with you, because you do not accept the foundations of the science. This is the wrong thread for you to visit. You should be trying to educate yourself on the more basic aspects of the science. Since you yourself have identified your acceptance of paleo studies as a blocking point, and yet you have seemingly misunderstood the relevance of those studies, I would suggest that you turn your attention away from that to other things. Develop a more firm understanding of the radiative physics behind greenhouse gas theory. Understand why it would be bizarre if the planet were not warming. From there, you can look in detail at each of the different periods in earth's history, and how CO2 played an important role in every climate change event in the past billion years. From there, you will be ready to move forward and begin to make value judgments such as whether or not the current rate of warming is alarming, or whether the dangers of anthropogenic climate change are an important and urgent factor in motivating people to more aggressively do what, as you have pointed out, really must be done anyway. Until you have thoroughly filled those to failings in your knowledge (the foundations of the science, and the facts behind all past climate change on the planet), you are not equipped to discuss any other issues.
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  16. 12, Camburn,
    20 or 30 years can easily be a cycle, rather than a change.
    You would not say this if your understanding of the science were better. Please study more before commenting further.
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  17. Camburn "Using a short term anomoly of only 20 or 30 years does not prove anything is happening climatically. 20 or 30 years can easily be a cycle, rather than a change." I find your position fascinating, Camburn. This article by HFranzen could well be written about you. We know the physics of CO2 and IR absorption, and have excellent measures of it's increase. Not to mention innumerable sets of evidence for considerable warming over and above natural forcings. We have no evidence for century scale 'variations' (Tamino has a lovely post on this, entitled Mathtubation), negative evidence (as in, disproof) about correlations of magnetic and cosmic ray effects (not to mention no solid physical hypotheses about how they would affect climate). And we have the observed noise and variation in the climate to judge that ~30 years is sufficient to accurately identify trends. 45 might be better (as that's when the standard deviation of the temperature anomaly flattens out with increasing sample duration), but 30 years is pretty solid statistically. So you combine "Type C" issues of values of long term averages with skipping over "Type A" issues in physics that show global warming is occurring due to our actions, adding in completely unsupported hypotheses about 'natural variation' and 'Mysterious Unknown Effects' (MUF's) from the sun unrelated to observed insolation. All to claim either it's not happening or it's a natural cycle - it's sometimes hard to tell which from your posts. Camburn, I would have to call your position one of 'denial'. It's certainly not science.
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  18. 13, Camburn,
    Our understanding of the effects of solar on climate is only beginning to be understood.
    You are grossly overstating an obvious truth. That we have more to learn about how the sun operates, or how the sun interacts with the earth's climate, does not in any way diminish the truth and strength of our understanding of the influence of CO2 on climate, or our ability to predict the rather dire consequences of ignoring that rather solid knowledge.
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  19. Sorry, in my previous post the acronym for 'Mysterious Unknown Effects' should be 'MUE', not 'MUF'. 'MUF' is short for the related 'Mysterious Unknown Force'(s), which I sometimes suspect are implicated in the weed levels of my shrubbery... Both MUE's and MUF's have the same explanatory value - none.
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  20. 19, KR, Oh. I thought you were trying to talk about people who sling Mysterious Unfounded Denial (MUD). But that's something else entirely.
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  21. Glad to see good responses: 1. This site is using AGW as a tool to promote alternative energy. So to say no one is a bit deceptive? 2. I understand the physics very well concerning co2. IF co2 was the only greenhouse gas it would be a slam dunk. It isn't. 3. Sphaerica: Your 1st description of a driver is correct. 4. KR: I can only suggest that you do a 100 year mean....then look at temperature within that mean. 5. Mysterious unkown cycles. Ya betcha. There are hints of these that are being uncovered. That is why they are uknown, and mysterious. 6. Our understanding of the co2 effect on climate is not really that good. That is why there is such a variation in the outcomes of climate models.
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  22. A confirmation of the above post concerning solar. What this shows us is that proxy reconstructions of past solar behavior based on the known at the time are prob flawed. Dr. Svalgaard had a paper recently, which I have posted on the solar link, that showed variation in TSI, even during the MM was neglible. When his results are incorporated into todays GCM's, the hindcast ability deteriorates. This is my point that there is a lot that we don't know, as it is obvious to all I would think. Dr. Svalgaard
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  23. Camburn @ 21: "This site is using AGW as a tool to promote alternative energy..." This is quite simply untrue. The implication is that John Cook (and others on this site) began with the premise "I want to see widespread use of alternative, renewable energy sources" and from there, worked backwards to develop justifications as to why alternative energy is preferable. The exact opposit is occurring--the realities of anthropogenic climate change require that we address CO2 emissions and energy infrastructure. Therefore, it is necessary to research and develop alternative energy sources to put the breaks on global warming.
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  24. Camburn: " This site is using AGW as a tool to promote alternative energy. So to say no one is a bit deceptive?" Isn't your statement more than "a bit" deceptive? Maybe I misunderstood it? Could you clarify?
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  25. Ok......let's try it this way. To address AGW, this site promotes the diminished use of fossil fuels as energy sources. And the alternative to fossil fuels are?
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  26. 25, Camburn, You appear to be purposely missing the point. The focus is not what the alternative to fossil fuels is, the focus is that there is a huge problem that needs to be addressed... solutions flow from considering the problem, not the other way around.
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  27. 21, Camburn,
    I understand the physics very well concerning co2. IF co2 was the only greenhouse gas it would be a slam dunk. It isn't.
    This statement shows that you do not, in fact, understand the physics at all. The fact that CO2 is not the only greenhouse gas is irrelevant. That you do not understand this is the proof that you do not understand the physics.
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  28. 21, Camburn,
    Your 1st description of a driver is correct.
    Then you must accept the premise that simply because CO2 has not often or definitively initiated climate change in the past, because it primarily has acted as a (critically important) feedback, this does not mean that CO2 cannot also act as a driver (using your definition for the term). To put it another way, there are very few natural mechanisms -- quite possibly none -- that can pump this much CO2 into the atmosphere in this short of a time frame. But this in no way changes the extreme radiative and climate related properties of concentrations of CO2, so one cannot claim to understand the underlying physics without also recognizing that, whether or not it has happened before, the change in CO2 that we ourselves are initiating in the atmosphere can most certainly have the same climate impact that it has in the past, which is to change the global mean temperature by 3˚C or more for every doubling of CO2. Do you refute this?
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  29. 21, Camburn,
    Our understanding of the co2 effect on climate is not really that good.
    False. 100% false.
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  30. 22, Camburn, Nothing you have posted on the sun so far on this thread has any direct bearing whatsoever on climate. Do you have any point at all with those posts? If so, can you please connect the dots?
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  31. Sphaerica: I will 100% support, all other items being constant, that a doubling of co2 from 280 ppmv to 560ppmv will increase temperature by 1.3C. I will not 100% support that doubling co2 will result in a temp rise of 3.0C. This has not been demonstrated in any study from paelo literature that I have read. If you can point me to a valid study that shows this, I am more than willing to read and digest it. I agree 100% that the rate of emission of co2 at present levels is foolhardy. I have stated a few of my reasons in a previous post.
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  32. Sphaerica@30. Yes, the items I have posted on the sun DO have a bearing on climate. Give me a day....I will post published papers showing paleo studies reflecting the influence of magnetic field strenth etc. They are written by Astrophysisists.
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  33. Sphaerica: Our understanding of the effect of co2 on climate is not really good. I will stand by that statement. As of yet, because we can not model clouds and the hydro cycle well, the current sensativity of our climate to co2 is in the type C science.
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  34. @camburn, #33 You may "stand by" that, but like with Luther's infamous "hier steh ich", you take your stand in an ill-advised fashion. For the truth is simply not on your side. Our understanding of the effect of CO2 on climate is good enough to know: we must cut back drastically and immediately on CO2 emissions, without increasing other GHGs, to prevent unmitigated disaster. It is already too late to prevent disaster, we are going to go through a stressful time worse than any since the Black Death, but it will be much, much worse if we don't cut back now.
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  35. 31, Camburn,
    This has not been demonstrated in any study from paelo literature that I have read.
    Any? Any? Are you serious? This is quite simply an unbelievable statement. Start here. You can also look here for more. If you want to argue that there is a chance that climate sensitivity is low because some studies show it (low meaning 2˚C), that's one thing, but to actually say that you've never seen any? That's quite a statement to make.
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  36. 32, Camburn, I don't need a list of more papers. I need to understand how two studies that discuss the "F10 Flux" in any way affect climate, which is to say, they are interesting studies of the mechanics and machinations of the sun, but that does not of itself require or even imply that such issues have anything to do with climate. The sun is the source of energy in the climate system, but it is also a fairly constant source of that energy. To claim otherwise, you must produce the proof which has been woefully absent to date and does not yet exist that in anyway clearly describes a mechanism and demonstrates some correlation between the behaviors being discussed and climate. Without this, cries of "F10 Flux Sun Magnetism Cosmic Ray Brouhaha" are nothing more than hand-waving distractions.
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  37. 33, Camburn,
    Our understanding of the effect of co2 on climate is not really good. I will stand by that statement.
    So you stand by a subjective and quite honestly indefensible claim. But we are wandering far off-topic. Dr. Franzen's post discusses how to discuss climate science with deniers, based on their level of acceptance of the science, as usefully divided by Dr. Franzen into Type A, Type B, and Type C. You refute all three types in various ways, so discussion with you is pointless, because your positions are unscientific and based purely on your own subjective perspective, rather than any factual basis. As such, there is no argument that you cannot refute by simply beginning any sentence with the magic words "I believe..."
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  38. Camburn 1. This site is using AGW as a tool to promote alternative energy. So to say no one is a bit deceptive? Ah, the familiar sound of conspiracy theories... better meds are suggested, as this cannot be taken seriously. 2. I understand the physics very well concerning co2. IF co2 was the only greenhouse gas it would be a slam dunk. It isn't. Evidently you don't. The physics of CO2 and it's effect on the greenhouse effect are a Type A kind of knowledge; your assertions otherwise indicate that you need to work on your physics. 3. Sphaerica: Your 1st description of a driver is correct. Then you understand that sometimes things act as feedbacks, and at other times (like now) when changed independently of temperature, they act as forcings? Like anthropogenic CO2? 4. KR: I can only suggest that you do a 100 year mean....then look at temperature within that mean. Over a 100 year mean, the temperature has risen. Over a 30 year mean, the temperature has risen much faster, and out of sync with natural forcings. Hence the 'unnatural' forcing of CO2 is responsible for that. And 30 years is plenty of time for the trend to emerge from noise and internal variation. 5. Mysterious unkown cycles. Ya betcha. There are hints of these that are being uncovered. That is why they are uknown, and mysterious. "Assertions made without evidence can be dismissed without evidence" - Christopher Hitchens. 'Nuf said. 6. Our understanding of the co2 effect on climate is not really that good. That is why there is such a variation in the outcomes of climate models. Really. Seriously. You want to produce some references that demonstrate that unsupported statement? --- So - assertions that well known physics such as CO2 and IR effects are not actually known, misunderstandings of feedback/forcings, evident lack of knowledge of statistics, assertions of 'cycles' without any evidence thereof (especially evidence that stands up to a statistical analysis), and more claims that we don't know anything. Denial, Camburn, this is all just denial.
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  39. KR: Where did I assert that the physics of co2 is not known? I think you have missed some of my posts. I agree 100% that a doubling from 280 to 560, all other things constant, will result in 1.3C warming. 30 years. From 1917-1944 we had a warming of 1.2C From 1980-1998 we had a warming of 1.3C Source Hadcrut variable adjusted global mean. The rate of warming is the same now as it was in the early-mid 1900's. According to the soon to be published paper by co-author Dr. Svalgaard, TSI has varied very little in the 1900's. So TSI is not the reason for the rise in the early-mid 1900's, just as it is not the reason for the drop of the LIA. climate models. We know that there are climate models with a prediction of 1.7 on the low end and climate models with a prediction of over 6C on the high end. Yes, there are variations on the amount of co2 emissions within these models, but co2 is not the only variant. As far as feedbacks and forcings, the variability within the literature and the models speaks for itself does it not?
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  40. 39, Camburn, Your posts are full of misinformation, and off topic, and should be deleted from this thread. It does not exist for you to promote your nonsense. If you wish, find another thread and re-post there.
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  41. 39, Camburn, For the record, however, anyone can address your nonsense by looking on this very site at: It's the Sun! (clearly outlines the increase in solar activity in the first half of this century which contributed to warming in that period, and the leveling off after 1950 which fails to account for recent warming). How do volcanoes drive climate (clearly outlines the cooling caused by large volcanic activity prior to 1920, and the dearth of volcanic eruptions that contributed to warming between 1920 and 1950). Rate of warming this century (clearly demonstrates that warming in the early half of this century is not comparable in rate to recent warming). How sensitive is our climate (clearly outlines the logic pointing to the high probability of a climate sensitivity of at least 3C.) Simpler version on climate sensitivity Really, Camburn, with as little as you understand, and admit to misunderstanding, I would think that you would spend more time studying and learning, and less time promoting the same old stale, foolish and thoroughly debunked arguments. Readers, beware of the oft repeated nonsense. Don't take your information from blog comments. Get it from better sources.
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  42. Sphaerica: Advances in science happen all the time. One of the advances is in how TSI flucuates. The paper that Dr. Svalgaard authored confirmed this. His credentials are impecable. His findings do not confirm a variability in TSI in the early-mid 1900's large enough to account for the increase in temperature. I posted the source for my data concerning rate of warming. I will leave it for the interested to confirm their own opinion. It would seem Bertrand's research on solar agrees with Dr. Svalgaard. "Bertrand was investigating the effect of solar and volcanic influence on climate and concluded "these are clearly not sufficient to explain the observed 20th century warming and more specifically the warming trend which started at the beginning of the 1970s".
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  43. Sphaerica: The topic of this thread is the uncertainty in global warming science. I am trying to show why they exist.
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  44. 42, Camburn, The work you are posting about (yet without providing links to the sources, so that your statements can be confirmed) appears to contradict existing work. Good. That means that science is advancing, and that peer review works, and that denial BS about peer review stifling contrarian research is poppycock. At the same time, no one paper is going to instantly overturn all of climate science. A paper by Svalgaard updating the TSI record will do nothing more than just that, and is likely to be disputed at least by some, but if it is correct, then good. A paper by Bertrand attempting to refute the explanation behind all observed early 20th century warming will have a very long way to go to be able to make that claim in one single paper. And what does he provide as an alternate cause for that warming? I'm afraid that "mysterious random natural variation" doesn't cut it. Still, it is convenient for you to argue from papers that have not yet been published. I find it curious that you put so much weight behind as yet unpublished works, and yet until this point have so gleefully dismissed the science which already exists. Doesn't this strike you as somewhat... arbitrary? As far as your made up data on the rate of warming... thanks, I'll trust someone else.
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  45. 43, Camburn, No, you're trying to pretend that such uncertainty exists everywhere, by claiming that you personally believe nothing.
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  46. Sphaerica: I have read Dr. Svalsgaards upcoming paper. He is so pre-eminent in his field that what he authors will for sure be robust. As far as Bertrand, I got the reference from this site from a link you posted for me to read. It was referenced by the author of the thread how do the volcanoes drive climate. I do not dismiss the science that already exists. I examine the papers, in fact I have purchased papers just to read them if I feel they are credible. I have read the 2007 IPCC report from cover to cover. Not the political one, but the WG report. Peer review is peer review. Some poor papers get through it, some good papers don't survive it. Just because a paper is peer reviewed does not make it credible. It is the aftermath, once one can view the source codes and supporting documents, that makes it credible. I will use TSI as an example. There are many peer reviewed papers that show different levels of TSI. This is one of the reasons that Dr. Svalgaard started looking for other proxies to form a credible record. We shall see how it stands the test of time. I don't make up data. I posted the source. Woodfortrees.org is a most wonderful site that allows one to do analysis.
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  47. Camburn At the core, your issue appears to be confusing the fact that "There are uncertainties of some level in all things" with "We cannot be certain about anything". This is an error. As an example, Barton Paul Levenson has assembled a list of historic climate sensitivity measurements. Examining this list, the uncertainties in sensitivity have decreased as our knowledge increases: The more we learn, the less uncertain we are. There's no justification for claiming otherwise.
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  48. KR: And then we have this. A paper that discusses the range of different TSI measurements in the present and its potential effects on climate. The TSI undertainty is not insignificant and has a large bearing on understanding. This is crucial to modeling etc. Scafetta
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  49. KR: Even with present papers there is a large range of uncertainty. From less than 1 to more than 4.
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  50. Camburn - Scafetta has previously published papers of, well, questionable value on this subject, and in his 2009 paper has failed to provide enough information for replication and testing. In particular, Scafetta seems to attribute all climate changes to TSI, neglecting land use changes, internal variation, and volcanic activity. This 'single cause' approach is inherently flawed (see CO2 is not the only driver of climate). I cannot take Scafetta seriously until he improves his game considerably - and your consideration of that as a source indicates that you're not checking them very carefully. --- As to climate estimates - checking the IPCC, the likely range (>60%) is within 2C to 4.5C per CO2 doubling, with much less certainty on the upper end of the range. There is estimated to be <10% chance of it being below 1.5C. You seem to keep betting on the low end - the odds are against you.
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